Formation Of Layer Research Articles

Formation of build-up in a cement kiln preheater: qualitative and quantitative mineral characterisation

Extracting more information about the reactions and parameters governing the formation of build-up in the preheater systems of clinker burning lines could be an efficient way of better attenuating build-up formation. In order to control the appearance of build-up, diagnosis steps of mineralogical analysis application for process optimisation (MAA-PO) are suggested. Mineralogical characterisation was carried out on three samples taken from different layers of the same build-up. Qualitative and quantitative X-ray diffraction, chemical analysis and Fourier transform infrared spectroscopy revealed that ternesite is the key mineralogical phase responsible for the growth and consolidation of build-up. Its appearance is governed by solid–solid reactions promoted by the available sulfate liquid phases, mainly calciolangbeinite, as well as C12A7 and C4AF. The hot-powder calcination degree, amount of sulfur trioxide, lime saturation factor, silica ratio and alumina ratio are the operational data that were correlated to the mineralogical analysis of build-up. Based on this correlation, it is possible to predict the reaction kinetics involved in each layer formation and to estimate the development time of each. The results showed that MAA-OP is a promising novel approach to optimise the process parameters in clinker production.

Corrosion of AISI1018 and AISI304 steel exposed to sulfates

This research analyses the behavior of corrosion, durability, and quality of reinforced concrete samples coated with two different materials when exposed to contaminated soil with sulfates. The initial assessment involved evaluating the water absorption rate of the coating materials before and after exposure to a solution containing 3% Na2SO4 + 3% MgSO4 + 3% K2SO4 + 3% CaSO4 to determine their durability. The corrosion potential and linear polarization resistance technique were employed to measure the corrosion rate. Carbon steel and AISI 304 steel bars were tested alongside a stainless counter electrode. The findings indicate that the solvent-based coating exhibited superior performance, demonstrating reduced corrosion and water absorption rates. Additionally, the presence of sulfates led to the formation of a surface layer on the concrete, initially aiding in limiting water penetration. However, over time, this layer eventually causes damage to the concrete from the inside out.

Fabrication and performance evaluation of polycarbonate/polyvinyl alcohol–titanium dioxide thin‐film nanocomposite membranes for water treatment

AbstractIn recent years, there has been growing interest in using polymer nanocomposite membranes as a more advanced method for removing pollutants from water and treating wastewater for various purposes. In this study, thin‐film nanocomposite (TFN) membranes of polycarbonate/polyvinyl alcohol–titanium dioxide thin‐film (PC/PVA–TiO2) were fabricated by dip‐coating a PC substrate in a PVA/TiO2 solution. Various methods, including attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectroscopy, field emission scanning electron microscopy (FE‐SEM), atomic force microscopy (AFM), and water contact angle were utilized to assess the structural characteristics of the produced membranes. The PC/PVA thin‐film composite (TFC) and PC/PVA–TiO2 TFN membranes were then examined in a submerged membrane system to evaluate their effectiveness in filtering humic acid (HA) under various vacuum transmembrane pressure (0.3 and 0.6 bar) condition. The FTIR‐ATR results confirmed the formation of the active layer of PVA/TiO2 nanoparticles (NPs). It was observed that adding 1 wt.% of TiO2 NPs to the active layer of PVA/TiO2 significantly enhanced the water contact angle from 77.5° for PC support to 55.3° for PC/PVA–TiO2 (0.1) TFN membranes. Furthermore, the FE‐SEM results confirmed the formation of an active layer of PVA/TiO2 with a thickness of 237.87 nm. The pure water flux increased from 101.64 L/m2h for the PC/PVA TFC membrane to 144.02 L/m2h and 199.09 L/m2h for the PC/PVA–TiO2 (0.05) and PC/PVA–TiO2 (0.1) TFN membranes, respectively. Also, the results revealed that at lower transmembrane pressure, all membranes showed higher value in HA removal as compared to when higher transmembrane pressure was used.

Mitigating the Kinetic Hysteresis of Co‐free Ni‐rich Cathodes via Gradient Penetration of Nonmagnetic Silicon

Co‐free Ni‐rich layered oxides are considered a promising cathode material for next‐generation Li‐ion batteries due to their cost‐effectiveness and high capacity. However, they still suffer from the practical challenges of low discharge capacity and poor rate capability due to the hysteresis of Li‐ion diffusion kinetics. Herein, based on the regulation of the lattice magnetic frustration, the Li/Ni intermixing defects as the primary origin of kinetic hysteresis are radically addressed via the doping of the nonmagnetic Si element. Meanwhile, by adopting gradient penetration doping, a robust Si‐O surface structure with reversible lattice oxygen evolution and low lattice strain is constructed on Co‐free Ni‐rich cathodes to suppress the formation of surface dense barrier layer. With the remarkably enhanced Li‐ion diffusion kinetics in atomic and electrode particle scales, the as‐obtained cathodes (LiNixMn1‐xSi0.01O2, 0.6 ≤ x ≤ 0.9) achieve superior performance in discharge capacity, rate capability, and durability. This work highlights the coupling effect of magnetic structure and interfacial chemicals on Li‐ion transport properties, and the concept will inspire more researchers to conduct an intensive study.

Surface Migration of Fatty Acid to Improve Sliding Properties of Hypromellose-Based Coatings

Hypromellose (HM) is a cellulose-derived polymer of pharmaceutical grade that forms easily from thin films and coatings. As few studies concern HM-formulated systems, this study focuses on the formulation of HM films by incorporating a fatty acid additive, making it possible to control surface properties such as wetting and slip behavior for pharmaceutical or medical applications. The results show that the addition of a very small amount (from 0.1 to 1% w/w) of fatty acid additive reduces HM film affinity for water and water vapor transmission rate, while film appearance and gloss are rather preserved. Surface properties were probed using wettability measurements, Tapping Mode AFM, ATR-FTIR spectrometry, and friction measurements. Tapping Mode AFM images show that the surface roughness reduces by up to 65%. Wettability results show that the surface energy decreases from 43 to 31 mJ.m−2, whereas surface FTIR spectrometry measurements demonstrate that fatty acid molecules migrate on the surface of the formulated films, the driving force being the microphase separation between the polar HM macromolecules and the hydrophobic additive, leading to the formation of a weak boundary layer with poor cohesion. As a consequence, the surface coefficient of friction significantly reduces from 0.38 to 0.08, and fatty acid molecules thus act as a lubricant, improving the sliding properties of HM-based coatings.

Consequence of coherent Cu5Zr precipitates and Cu2O passive layer formation on the corrosive behaviour of additively processed Cu-Cr-Zr alloy in simulated seawater

Abstract The Cu-Cr-Zr copper alloy is known for its outstanding electrical conductivity and fatigue strength. However, the corrosion behaviour of the copper alloy should also be taken into account when adopting it in industrial applications, especially in the marine environments. This research aims to fabricate Cu alloy coupons using the Laser Powder Bed Fusion (LPBF) technique and subsequently test their corrosive performance in simulated seawater. This research confirms that the Cu5Zr precipitate formation during the LPBF process and the Cu2O passive layer formation were the main reason for the enhanced corrosive behavior of the LPBFed copper alloy. The OM (Optical Microscope), FESEM (Field Emission Scanning Electron Microscope) images supported in evaluating melt pool formations and irregularities, and also confirmed the polycrystalline structure. The diffraction pattern from the TEM (Transmission Electron Microscope) analysis confirmed the formation of Cu5Zr precipitate and grain size distribution, while their orientations were obtained from the EBSD (Electron Based Scattered Diffraction) EBSD analysis. Micro hardness was executed on the scanning and building directions, and it was found that the building direction possessed higher hardness of 54 HV0.3 which was 5% higher than in the scanning direction. This significant fluctuation in the hardness value is due to the closely packed equiaxed and columnar grains along the outer and inner regions of the melt pools. Potentio-dynamic polarization (PD) and electrochemical impedance spectroscopy (EIS) tests were performed on the printed copper alloy parts for various immersion periods of 0, 9, 18 and 38 h. Further, the XRD (x-ray Diffraction) analysis was performed on the corroded surface and it confirmed the Cu2O passive layer and the occurrence of Cu5Zr precipitate. The occurrence of Cu5Zr precipitates and Cu2O passive layer formation helped attain the maximum polarization resistance of 2033.8 ohm and minimum current density of 5.928 × 10−6 A cm−2 with minimum surface roughness of 3.447 μm.

Enhanced hydroxyl radical generation by zero-valent iron/ethylenediamine tetramethylene phosphonic acid for Cr(VI) reduction and 2,4-dichlorophenol degradation

Zero-valent iron (ZVI) has emerged as a promising material for water remediation in recent years. However, the formation of a passivation layer on the surface of ZVI significantly reduces its reactivity. Ethylenediamine tetramethylene phosphonic acid (EDTMPA), a chelating agent, aids in the prevention and passivation of ZVI. This chelating agent has been used in combination with ZVI to remove 2,4-dichlorophenol (2,4-DCP) and hexavalent chromium Cr(VI) simultaneously. In this study, the addition of EDTMPA significantly enhanced the removal efficiencies of Cr(VI) and 2,4-DCP by 7.7 to 10 times compared to ZVI reaching complete removal of Cr(VI) and 80% removal of 2,4-DCP within 120min. Quenching and probing experiments have shown that hydroxyl radicals (•OH) serve as the predominant reactive species responsible for the degradation of 2,4-DCP. Meanwhile, pristine ZVI effectively reduced Cr(VI) to the less hazardous Cr(III) and reacted with oxygen in water to generate Fe(II) and hydrogen peroxide (H2O2), both critical for initiating the subsequent Fenton reaction. The addition of EDTMPA effectively mitigated the formation of the passivation layer on the surface of the ZVI, maintaining its reactivity. The ZVI/EDTMPA system offers an effective method for simultaneous remediation of Cr(VI) and 2,4-DCP by optimizing the application of ZVI.

Augmented Depletion Development Technology Assessed Across US Shale Plays

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 217792, “Assessment of Augmented Depletion Development Technology Across US Shale Plays,” by Ahmed Merzoug, SPE, Texas A&M University, and Vibhas J. Pandey, SPE, ConocoPhillips. The paper has not been peer reviewed. _ The concept of augmented depletion development (ADD) was introduced to the industry through a pilot project conducted in the Bakken play in the US. These wells are openhole wells drilled within the fractured network of a pad. They are not fracture stimulated deliberately but do produce and contribute to the overall production of the lease. In this study, numerical modeling is used to understand the potential performance of these wells in several plays across the US. The learnings from this study can be used as a benchmark for operators that are planning on implementing such wells in their field development programs. Theoretical Basis of Study The concept of ADD can be modeled using a similar approach to the analytical solutions developed for flow into a multistage fractured horizontal well. In these wells, several regimes can be identified, such as transient linear flow and boundary-dominated flow. In previous work in the literature that proposed a method for analyzing production data of linear flow of fractured gas wells, fractures were assumed to have infinite dimensionless conductivity. Those researchers proposed a solution for a constant bottomhole-pressure liquid flow that is described in the present complete paper by a series of equations. For the case used by the present authors, a well spacing of 300 ft is assumed, implying that the perpendicular distance from the wellbore to a corresponding boundary is 150 ft, which is half the spacing between the fractured well and the ADD well (assuming each well drains half the fracture length). To elaborate further for better understanding of production, a plot of product of cumulative dimensionless rate and formation permeability (as a proxy for cumulative rate) while assuming all other properties behave the same shows that, with higher permeability, the recovery potential not only increases but also appears to accelerate. This supports the concept that, during the time of production of ADD wells, it is preferable to have higher permeabilities that can support faster production in zones that the primary wells may not drain effectively. The results of the analytical equation are for only one fracture but can be readily extended to multifractured horizontal wells using superposition methods. Methodology This study uses physics-based numerical modeling to simulate the performance of ADD wells in different plays. The numerical code simulates wellbore flow, hydraulic fracturing, geomechanics, and reservoir flow, all in the same package. The fracture and reservoir mesh are independent. The flow between the matrix and the reservoir is calculated using the 1D submesh approximation to reduce the computation expenses with higher accuracy. The hydraulic fracturing propagation algorithm uses a tip-tracking algorithm to allow the use of larger grid size without compromising accuracy in layered formations. The fracture conductivity is calculated with stress changes. The conductivity profile changes from a propped fracture into an unpropped fracture. The unpropped fracture conductivity is an underlying assumption used in this study. The collision between fractures initiated from different wells also is an assumption in this study.

Oxidation Behavior of Lightweight Al0.2CrNbTiV High Entropy Alloy Coating Deposited by High-Speed Laser Cladding

High-temperature oxidation resistance is the major influence on the high-temperature service stability of refractory high entropy alloys. The oxidation behavior of lightweight Al0.2CrNbTiV refractory high entropy alloy coatings with different dilution ratios at 650 °C and 800 °C deposited by high-speed laser cladding was analyzed in this paper. The oxidation kinetic was analyzed, the oxidation resistance mechanism of the Al0.2CrNbTiV coating was clarified with the analysis of the formation and evolution of the oxidation layer, and the effect of the dilution rate on high-temperature performances was revealed. The results showed that the oxide layer was mainly composed of rutile oxides (Ti, Cr, Nb)O2 after isothermal oxidation at 650 °C and 800 °C for 50 h. The Al0.2CrNbTiV coating in low dilution exhibited better oxidation performance at 650 °C, due to the dense oxide layer formed with the synergistic growth of fine AlVO3 particles and (Ti, Cr, Nb)O2, and higher percentage of Cr, Nb in (Ti, Cr, Nb)O2 strengthened the lattice distortion effect to inhibit the penetration of oxygen. The oxide layer formed at 800 °C for the Al0.2CrNbTiV coating was relatively loose, but the oxidation performance of the coating in high dilution improved due to the precipitation of Cr2Nb-type Laves phases along grain boundaries, which inhibits the diffusion of oxygen.

Fabrication of PDMS/FA superhydrophobic coatings and its self-cleaning and anti-icing performance

Superhydrophobic coatings have garnered immense attention in recent years. Nevertheless, the creation of superhydrophobic coatings is often associated with high production costs and comparatively intricate fabrication processes. In this paper, we utilize cheap and easily available ultrafine fly ash(FA) as the main raw material to replace the expensive filler substances traditionally used for constructing rough structures, and Polydimethylsiloxane(PDMS) as a low surface energy modification to construct FA-based superhydrophobic coatings by a simple spraying method. The PDMS/FA coating surface exhibits a water contact angle(WCA) of 157.65°and a water sliding angle(WSA) of 2.00°. The irregular morphology of the FA is conducive to forming a rough texture on the coating surface, which captures more air, leading to the formation of a stable air layer. Molecular dynamics (MD) simulations provide an insight into the anti-wetting mechanism of the superhydrophobic surface through an analysis of energetic and dynamic properties. PDMS/FA coatings remain superhydrophobic at 150°C, in UV, and in varying pH environments. In addition, PDMS/FA coatings offer excellent mechanical, self-cleaning and anti-icing properties. This innovative approach to superhydrophobic coating, utilizing solid waste material as a basic material, demonstrates potential applicative value in fields such as self-cleaning and anti-icing.

The oxidation resistance of Ni nanoparticle incorporated SiOC coating for TiAl alloy

In this work, SiOC coatings incorporated with Ni nanoparticles were fabricated on γ-TiAl alloy by dip-coating. The microstructure and high temperature oxidation behavior of the SiOC-Ni coatings with different Ni contents were investigated. Results showed that the incorporation of Ni nanoparticles improved the oxidation resistance of the SiOC coating at 850 ℃. During thermal exposure to air, the incorporated Ni particles would react with both oxygen and the SiOC coating, forming NiO and Ni2Si, respectively, therefore changing the structure of the SiOC coating. The generation of NiO and Ni2Si is beneficial in reducing the oxygen partial pressure at the coating/substrate interface, thereby facilitating the formation of a protective aluminum oxide layer.

The significance of bilayer window (CdS:O/CdS) on the performance of CdTe thin film solar cells

Ultrathin and compact CdS:O/CdS bilayer window in CdTe solar cells has higher potential for enhanced p-type doping, reduced Te diffusion, and improved power conversion efficiency (PCE) compared to traditional single-layer CdS or CdS:O windows. In this effort, we used a two-gun RF sputtering equipment to deposit compact CdS:O(∼50 nm)/CdS(∼50 nm) bilayers onto the borosilicate and ITO-coated glass substrates at low temperature (≤ 250 oC). Intriguingly CdS:O/CdS bilayers retain its hexagonal {0002} preferential orientation but with around 10.58% optical bandgap (Eg) increment compared to CdS (Eg≈2.32 eV) of equal thickness (∼100 nm). Close-spaced sublimation (CSS) technique was used to deposit the CdTe thin film onto the CdS and CdS:O/CdS layers at 550 °C. The effect of CdS and CdS:O/CdS layers on the microstructural and morphological features of CdCl2-treated CdTe films were critically analyzed revealing a promising {0001}/{111}-like partial-epitaxy presumably due to the preferential cubic CdTe growth along the <111> orientation. The CdTe films grown over a CdS:O/CdS layer exhibited smaller average crystallite and grain sizes than those grown over a single CdS layer. An essential finding was the formation of an optimal intermix layer of CdSxTe1-x, particularly evident in the CdTe films grown on the CdS:O/CdS bilayer. To comprehensively explore the effect of CdS:O/CdS window layers on PCE, complete CdTe solar cells were fabricated using three different window layers: CdS, CdS:O, and CdS:O/CdS, which are all considered as rudimentary as no layer optimization was performed. Notably, CdTe solar cell that incorporates the CdS:O/CdS bilayer window exhibited the most promising performance among all the tested rudimentary cells and corroborated the numerically simulated findings conducted by the SCAPS-1D simulator.

Barnacle-inspired and polyphenol-assisted modification of bacterial cellulose-based wound dressings for promoting infectious wound healing

Bacterial cellulose (BC) is an ideal candidate for wound dressings due to its natural origin, exceptional water-holding capacity, pliability, biocompatibility, and high absorption capability. However, the lack of essential antimicrobial activity limits its biomedical applications. This study reported BC-based wound dressings containing silk fibroin protein (SF), offering the potential for biomimetic properties, and (−)-epigallocatechin-3-gallate (EGCG) for polyphenol-assisted surface modification to promote infectious wound healing. Glycerol was used as the carbon source to promote the formation of an adhesive layer by facilitating the β-sheet folding of SF, and different concentrations of EGCG were employed to interact with SF through strong hydrogen bonding facilitated by the polyphenolic groups. The functionalized membrane exhibited outstanding water-holding capacity, swelling ratio, and degradation properties, along with enhanced hydrophilicity, adhesiveness, and a remarkable free radical scavenging ability. Both in vitro and in vivo experiments confirmed its potent bacteriostatic activity. The composite membrane displayed excellent biocompatibility, including cellular and hemocompatibility. Importantly, it effectively promoted wound healing in murine back infections. These findings suggest the significant feasibility of the innovative modification approach, and that functionalized membranes have great potential as wound-dressing materials for infection management in future clinical applications.

Oxidation of Sintered Refractory Alloy (Ni3Al)

Ni3Al is a superalloy which is of particular interest at high temperatures due to its high resistance to oxidation with the formation of a protective oxide layer that performs better than NiO and Cr2O3. Among the factors likely to affect the reaction mechanism and modification of the oxidation kinetics, the surface state appears to be a very important parameter. In the case of sintered materials, the surface condition will be linked to the porosity of the material and therefore to densification. This work essentially has two parts. The first consists of developing Ni3Al sinters intended for oxidation, studying the densification mechanisms and bringing together the results obtained by dilatometry at variable temperature and by differential thermal analysis which made it possible to demonstrate sintering in a reactive liquid phase extremely fast SHS type, with instantaneous formation of the Ni3Al phase. The second part is devoted to the isothermal oxidation between 1100 and 1350°C of cubic-shaped sinters (4mm edge) under a flow of oxygen for 24 hours. The shape of the parabolic curves is correlated with morphological and microstructural observations to deduce the diffusional kinetic regime which controls the speed of the reaction. On the other hand, these observations highlighted a very strong adhesion due to the indentations of the Al2O3 oxide in the metal at the oxide/metal interface. Various techniques (Density – XRD – SEM and Microanalysis) to characterize the sinters and the oxidation products complete our study.

Study on automatic anti-icing effect and rheological properties of asphalt based on SiO2 nanowires

This study addresses the issue of severe traffic disruptions caused by winter road icing by enhancing traffic disaster resilience. A primary road-surface ice-control technique, known as "anti-icing", is proposed. A nanomaterial with outstanding superhydrophobic properties was prepared and incorporated into asphalt to create hydrophobic ice-inhibiting modified asphalt. Extensive experimentation confirmed that the hydrophobic ice-inhibiting modified asphalt had desirable characteristics, achieving impressive anti-icing performance. The experimental results indicated that the synthesised material was superhydrophobic, with a contact angle exceeding 150° and its primary component being SiO2. At the microscopic level, the synthesised superhydrophobic material exhibited a complex microstructure, primarily characterised by entangled nanowires and a small quantity of nanoparticles. In addition, the material demonstrated stable thermal properties and good compatibility with asphalt. The superhydrophobic material significantly enhanced the hydrophobic properties of asphalt, and the prepared asphalt mixture effectively inhibited the formation of surface ice layers, consequently reducing the surface ice accumulation and ice formation efficiency by 69.11% and 19.01%, respectively, for the asphalt containing 15% superhydrophobic material relative to the base asphalt. In conclusion, the superhydrophobic material prepared in this study enhances the performance of asphalt while imparting de-icing functionality, making it a novel road surface "anti-icing" material that improves winter traffic resilience.

Utilization of boron particulate wall conditioning in the full tungsten environment of WEST

Over a series of experiments performed on the WEST device we have demonstrated the ability to perform controlled impurity injections and improve overall wall conditions. Positive changes to overall machine conditions are evidenced by reduced native impurity content after injection as well as decreases in radiated power and reductions in recycling. These results are consistent with the formation of a gettering layer which provides a particle sink and a reduction of source terms. We also observe a reduction in overall Zeff at the conclusion of the powder injection period consistent with a reduced impurity burden within the plasma. Finally, we have demonstrated a minimal injection quantity required to affect a positive change in wall conditions. These results confirm that plasma assisted deposition of conditioning material through particulate injection shows substantial promise as a supplemental wall conditioning technique.

Microstructure and corrosion properties of Al1-xWxN coatings for potential use in gas turbine blades

Herein, a numerical approach of Al1-xWxN thin film coatings on Inconel 738LC superalloys for thermal barrier applications has been studied and the experimental analysis includes deposition of Al1-xWxN films on Si (100), glass and transparent quartz substrates at 40 % N2 flow rate using a dual target DC reactive magnetron sputtering technique to investigate the morphology, microstructure, chemical bonding and corrosion behaviour. AFM analysis revealed the rms roughness, Sq and average roughness, Sa increased with the increasing W content from 22 to 70 at.%. It was found that Al1-xWxN films tend to form tiny valleys on the film surface because the values of surface skewness, Ssk lie below zero. The TEM image showed a branched snowflake structure for the specimen of Al0.58W0.42N films with discrete spots in the SAED pattern, confirming the microcrystalline nature. The blue-shifting of Ecorr towards positive potential confirmed the lower corrosion resistance of WN films than those of AlN. XRD spectra of Al0.58W0.42N films showed an amorphous nature devoid of peaks, which is also confirmed by the SAED pattern. The quasi-passive oxide layer formation was spontaneous for WN films compared to the AlN films. The bending vibrations of AlN and WN showed the coordination environment of the metal centre in the Al1-xWxN films. The computational results indicated that the thermal barrier properties of Al1-xWxN films decreased with the increasing W content, i.e., AIN > Al0.58 W0.42N > WN.

Unveiling the impacts of salts on halotolerant bacteria during filtration: A new perspective on membrane biofouling formation in MBR treating high-saline organic wastewater

In recent decades, membrane bioreactor (MBR) has been prevalently employed to treat high-saline organic wastewater, where the halotolerant microorganisms should be intensively utilized. However, limited works were devoted to investigating the biofouling characteristics from the perspective of the relationship between halotolerant bacteria and salts. This work filled the knowledge gap by exploring the biofouling formation mechanisms affected by high salinity. The results showed that the amount of negative charge on halotolerant bacteria surface was significantly reduced by high content of NaCl, probably leading to the obvious cell agglomeration. Despite the normal proliferation, the halotolerant bacteria still produced substantial EPS triggered by high salinity. Compared with the case of control without salt addition, the enhanced biofouling development was observed under high-saline conditions, with the fouling mechanism dramatically transformed from cake filtration to intermediate blocking. It was inferred that the halotolerant bacteria initially adhered on membrane created an extra filter layer, which contributed to the subsequent NaCl retention, resulting in the simultaneous occurrences of pore blockage and cake layer formation because of NaCl deposition both on membrane pores as well as on biofilm layer. Under high-saline environment, remarkable salt crystallization occurred on the biofilm layer, with more protein secreted by the attached halotolerant bacteria. Consequently, the potential mechanisms for the enhanced biofouling formation influenced by high salinity were proposed, which should provide new insights and enlightenments on fouling control strategies for MBR operation when treating high-saline organic wastewater.

Oil unsaturation degree dictates emulsion stability through tuning interfacial behaviour of proteins

The unsaturated vegetable oil is commonly incorporated as protein-stabilized emulsion into fat-substituted emulsified meat products (FSEMP), whose quality is closely related with the emulsion stability. Here, we systematically investigated the effects of oil unsaturation degree (UD) on the interfacial properties (structural changes, adsorption dynamics, interfacial rheology, adsorption layer thickness) of proteins and thus the emulsion stability. The oleic acid and linolenic acid were mixed with dodecane as model oils. Three types of proteins were selected as model emulsifiers (fibrous myofibrillar protein, MP; globular whey protein, WP; random-coiled sodium caseinate, SC). The proteins diffused slower to the higher UD interface, resulting in a lower interfacial pressure. This led to a larger droplet size of the higher UD oil emulsion upon emulsification. However, the proteins penetrated and rearranged faster at the higher UD interface ascribed to a more extensive structural unfolding, enabling the formation of stiffer and thicker adsorption layers. This contributed to a stronger short-term stability of MP- and WP-stabilized higher UD oil emulsion; while for the random-coiled SC, the higher UD oil emulsion was less short-term stable, which was primarily determined by the initial (larger) droplet size but not the interfacial layer properties. The stiffer layer at the higher UD interface was on the other hand less stretchable, which tended to yield when subjected to higher strain. This probably accounted for the weaker long-term stability of the higher UD oil emulsion, regardless of protein types. These results highlighted that the oil UD should be elaborately considered for the rational formulation of FSEMP.

A dynamic WUSCHEL/Layer 1 interplay directs shoot apical meristem formation during regeneration in tobacco.

De novo shoot apical meristem (SAM) organogenesis during regeneration in tissue culture has been investigated for several decades, but the precise mechanisms governing early-stage cell fate specification remain elusive. In contrast to SAM establishment during embryogenesis, in vitro SAM formation occurs without positional cues and is characterized by autonomous initiation of cellular patterning. Here, we report on the initial stages of SAM organogenesis and on the molecular mechanisms that orchestrate gene patterning to establish SAM homeostasis. We found that SAM organogenesis in tobacco calli starts with protuberance formation followed by the formation of an intact L1 layer covering the nascent protuberance. We also exposed a complex interdependent relationship between L1 and WUS expression and revealed that any disruption in this interplay compromises shoot formation. Silencing WUS in nascent protuberances prevented L1 formation and caused the disorganization of the outer cell layers exhibiting both anticlinal and periclinal divisions, suggesting WUS plays a critical role in the proper establishment and organization of L1 during SAM organogenesis. We further discovered that silencing TONNEAU1 prevents the exclusive occurrence of anticlinal divisions in the outermost layer of the protuberances and suppresses the acquisition of L1 cellular identity and L1 formation, ultimately impeding SAM formation and regeneration. This study provides a novel molecular framework for the characterization of a WUS/L1 interplay that mediates SAM formation during regeneration.